Pumps are known which include: a motor as a drive source; rotary vanes connected to the output shaft of the motor; a pump chamber accommodating the rotary vanes; a lid member covering the pump chamber; a water inlet (i.e., raw water inlet) provided in one side of the pump chamber for introducing raw water from outside; a water outlet (i.e., raw water ejection outlet) provided in another side of the pump chamber for discharging the raw water from the pump chamber; and a draining plate provided on a motor-side end portion of the output shaft. One example of such pumps is disclosed in Japanese Patent Application Laid-Open Publication No. 2009-264317 (hereinafter referred to as “patent literature 1”), which is designed to effectively prevent water from entering the motor via the output shaft.
Also known today are techniques and apparatus for purifying water pumped up by such a pump. The known purification apparatus generally includes: an evaporation device for producing vapor from raw water by heating the raw water with heat provided by a heat source (heat exchanger); a condenser for receiving the produced vapor from an evaporator provided at the last stage of the evaporation apparatus and condensing the received vapor into distilled water; and an vacuum device for reducing the pressure of air within the evaporator of the evaporation device below the atmospheric pressure. One example of such purification apparatus is disclosed in Japanese Patent No. 4139597 (hereinafter referred to as “patent literature 2”), which is designed to permit efficient use of heat by using heat of the vapor and condensed water as a heat source of the heat exchanger.
However, the pump disclosed in patent literature 1 above only has a pump function capable of introducing raw water into the pump chamber and transferring the raw water from the pump chamber to another place, and the purification apparatus disclosed in patent literature 2 above only has a purification function capable of refining raw water into distilled water.
Water consumption in the whole world has been increasing year by year, and it is said that about two-thirds of the world population will be troubled with water shortage in the year of 2025. Even today, about 1.1 billion people in the world are unable to obtain safe drinking water. Further, in developing countries, poisoning and diarrhea resulting from drinking unboiled water from contaminated soil is occurring as an everyday affair. There have also been reports that infections resulting from such water and unsanitary daily life water are the most primary causes of death and about 80% of diseases in the world. Thus, securement of sanitary water is an urgent need. Namely, there is a demand for a hybrid water pump having both a pump function and purification (or distillation) function.